20 research outputs found

    Immunohistochemical Study of Stellate Cells in Patients with Chronic Viral Heptitis C Histopathological study

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    Background: Chronic hepatitis is defined as liver inflammation that lasts for at least 6 months. The Hepatitis C virus is responsible for 60 to 70% of chronic hepatitis cases; the virus causes continued inflammation that slowly damages the liver, eventually leading to cirrhosis, liver failure, and, in rare cases, liver cancer. Aim of the work: To evaluate the changes in distribution and percentage of alpha-smooth muscle actin-positive hepatic stellate cells and the correlation with the degree of the fibrosis in cirrhotic livers, in patients with HCV chronic hepatitis. Material and methods: 50 hepatic core biopsies selected randomly were received from Histopathology Department at National Hepatology and Tropical Medicine Research Institute and examined for histopathological features using (hematoxylin and eosin), stage of hepatic fibrosis using stellate cell Masson s' trichrome stain, and examined for stellate cell activity using alpha smooth muscle actin (ASMA) immunostaining. Results: The relation between degree of ASMA expression by stellate cells and stage of fibrosis was highly significant with a p value <0.001, also the relation between degree of necroinflammation and degree of ASMA expression by stellate cells was highly significant with a p value <0.001. The relation between degree of necroinflammation and stage of fibrosis was highly significant with a p value <0.001. The relation between age of patient and stage of fibrosis also was statistically significant with a p value =0.012. The relation between age of patient and degree of necroinflammation was statistically significant with a p value =0.017. Conclusion: To summarize from hepatic core biopsies of patients suffering from chronic HCV, the number of active stellate cells was found to be positively associated with stage of hepatic fibrosis

    Multi-ethnic genome-wide association study for atrial fibrillation

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    Atrial fibrillation (AF) affects more than 33 million individuals worldwide and has a complex heritability. We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Immobilization of Cd, Pb and Zn through Organic Amendments in Wastewater Irrigated Soils

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    Due to the scarcity of water, raw sewage effluents are often used to irrigate arable suburban soils in developing countries, which causes soil contamination with toxic metals. Soil microorganisms involved in biochemical transformations are sensitive to heavy metals contamination. The study was designed to investigate the effect of organic amendments on the microbial activity of cadmium (Cd), lead (Pb) and zinc (Zn) fractions and their bioavailability in soils contaminated with wastewater irrigation. Three metal contaminated soils under wastewater irrigation were collected, ground, sieved and added to incubation jars. Two organic amendments: wheat straw and chickpea straw, were applied (1% w/w) to the soil before incubation for 84 days at 25 °C. The CO2-C evolution after 1, 2, 3, 5, 7, 10 and 14 days was measured and thereafter was also measured weekly. Soil samples collected at 0, 14, 28, 42, 56, 70 and 84 days after incubation were analyzed for microbial biomass carbon (MBC). Sequential extraction for metal fractionation of samples was carried out collected at 0, 28, 56 and 84 days. Three soils differed significantly in evolved MBC and ∑CO2-C. Chickpea straw addition significantly increased soil MBC as compared to the wheat straw. Organic amendments significantly increased ∑CO2-C evolution from the soils, which was higher from chickpea straw. The addition of crop residues did not affect total Pb, Cd and Zn contents in soils. The concentration of exchangeable, carbonate bound and residual fractions of Pb, Cd and Zn decreased (6–27%), while the organic matter bound fraction increased (4–75%) with straw addition. Overall, the organic amendments improved microbial activity and reduce the bioavailability of toxic metals in wastewater irrigated soils. Furthermore, organic amendments not only reduce economic losses as they are cheap to produce but also minimize human health risks from heavy metals by hindering their entry into the food chain
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